Applying to colleges is a hard enough task, but it was made even more difficult for Diana Gonimah when the political turmoil of Arab Spring in her home country, Egypt, briefly shut down communication with the outside world. Her high school closed for 20 days and she was barely able to call admissions officers in the U.S. to say, “Sorry, I can’t send my transcript for another month.”

PHILADELPHIA — Ancient pollen and charcoal preserved in deeply buried sediments in Egypt’s Nile Delta document the region’s ancient droughts and fires, including a huge drought 4,200 years ago associated with the demise of Egypt’s Old Kingdom, the era known as the pyramid-building time.